For many years, drive belts, V-belts, multi-vee-belts, and serpentine belts have been used to transmit power from the engine crankshaft pulley to accessories, like the power steering pump, air conditioning compressor, water pump, or cooling fans. Toothed Car Pulley Belt timing belts and timing chains, too, are accustomed to transmit power from the crankshaft to the camshafts, and some from the camshaft to camshaft, based on engine design.

The drive belt, timing belt, or timing chain won’t work very well, or for lengthy, if, with incorrect tension. A loose drive belt won’t drive the item reliably, slipping and producing noise. Conversely, an excessively restricted belt may cause item or pulley bearing damage. Various kinds of tensioner pulley keep long-term engine and item quietness and reliability.

Tightening or Loosening
Sometimes, maintenance or repair will demand tightening or loosening a tensioner pulley. Replacing a drive belt or timing belt, for example, would need you to loosen a tensioner pulley to make room for the brand new belt, as the new belt is smaller than the worn drive belt.

You will have to tighten a tensioner pulley, in most cases, after the installation of a new drive belt, or even to change for a stretched drive belt that hasn’t worn enough to warrant replacement. Stretch belts don’t need tensioner pulleys but are “stretched” into place utilizing a special tool-always use the special tool to prevent belt damage.

Tensioner pulleys generally fall into two categories: accessory-integrated (AI) and non-accessory-integrated (NAI). Think about AI tensioners as adjustable components, such as an alternator, and NAI tensioners as adjustable idler pulleys. There are three types of tensioner pulleys and many ways to loosen them.
Mechanical tensioner pulleys will be the simplest, many common, and least prone to failure. There is definitely one caveat, nevertheless, as mechanical tensioner pulleys need manual adjustment. This makes them susceptible to user error, resulting in insufficient or excessive belt tension. Additionally, they have to be adjusted to compensate for belt stretch over time.